Method of cooling finished stereotype printing plates



c. E. HOPKINS. METHOD OF COOLING FINISHED STEREOTYPE PRl-N-TING PLATES.

APPLICATION FILED JULYIZ. 1920.

Patented May 23, 1922.-

2 SHEETS-SHEET 1.

3mm? Mai m v C. E. HOPKINS. I METHOD OF COOLING FINISHED STEREOTYFE PRINTING PLATES. 1,416,714.,

APPLICATION FILED JULYIZ. i920.

Patented May 23, 1922.

2 SHEETS-SHEET 2.

amen? afazhZZakzhkq:

CHARLES E. HOPKINS, OF PLAINFIELD, NEW JEB/SEY.

METHOD OF COOLING FINISHED STEREOTYPE PRINTING PLATES.

Specification of Letters Patent.

Patented llllay 23, 1922.

Original application filed February 25, 1911, Serial No.- 610,834. Divided. and application filed April 2, 1917, Serial No. 159,117. Divided and this application filed July 12, 1920. Serial No. 395,560.

1'0 all whom it may concern:

Be it known that 1, CHARLES E. HOPKINS, a citizen of the United States, residing at Plainfield, in the county of Union and State of New Jersey, have invented a new and useful Method of Cooling Finished Stereotype Printing Plates, of which the following is a specification.

This is a division of my application Serial No. 159,117 filed April 2, 1917, which was a division of my application filed February 25, 1911, Serial No. 61053 1, which resulted in Patent No. 1,286,323, on a machine for making stereotype plates, patented Decemher 3, 1918.

This invention is for the purpose of cooling semi circular curved stereotype printing plates for use on the cylinders of rapid printing or rotary presses, particularly such as are in common use inproducing newspapers, and is designed mainly as a labor saving device whereby one man by manipulating certain handles and levers will be able to produce the stereotype printing plates completely finished, and cooled so they can be handled by the bare hands, in condition to be immediately attached to the printing press cylinder, and especially to provide an improved method whereby through the control of the contraction of the curved printing plate during the process of cooling, the operator will be able to produce plates of various curvatures or dimensions from the same casting chamber and further, through the control of the cooling fluid, deliver the plates practically dry and ready to be attached to the press cylinder; also to provide for con trolling the flow of cooling water itself.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings in which- Fig. 1 is a side elevation of a coolingmachine constructed in accordance with this invention;

Fig. 2 is a fragmentary detail thereof;

Fig. 3 is a sectional view of the same on the line 33 of Fig. 1;

Fig. 4 is an enlarged sectional view on the same line showing how the edge of the plate is held during one perlod of the operation;

Figs. 5 and 6 are similar views showing other positions of the plate, and

Fig. 7 is an end view of one of the rollers for supporting the plate with parts in sectlon.

This invention is concerned with the treatment of a curved stereotype printing plate after it has been cast, finished, and delivered by such a machine as is shown in my above mentioned Patent No.-1,286,323 or in any otherway. Assuming that the plate has been delivered in any desired way I will now describe the improved flexible cooling and drying mechanism employed, and explain how by controlling the contraction of the stereotype plateduring the cooling process I am able to produce plates of both less or greater diameter from the same casting chamber, also how by the'control of the cooling water I can produce the plate dry and ready for the press cylinders.

Curved stereotype plates, such as are used in producing newspapers, are of a semi-circiu'nfcrence equal to the length of the printed matter of a newspaper page, and vary in diameter from 13%; to 16%- inches.

It is often found that, although the printing faces of two different makes of web perfooting presses are the same yet the cylinders may vary in diameter an eighth of an inch, more or less, the difference being in the margins or space between the two printing halves of the circumference of the cylinders which form the top and bottom blank space or margins of the paper.

Owing to this variation heretofore it has been necessary to cast the plates in machines for each size, and again owing to there being a large variety of sizes of presses between the13-1- and 163; inch size (about 20) it has been considered impracticable to carry casting and finishing machines in stock. These difficulties 1 am now able to overcome. I find that an average sized curved stereotype plate will suddenly contract about ii in diameter when the cooling water engages its concavity, and as the cooling advances from the concave side through to the exterior the plate will slowly contract on the outside and counteract the interior contraction, and if left perfectly free the plate will resume its normal curvature. However if the curvedv plate is supported. in a manner so its straight edges are held against axial contraction during the cooling of the interior surface it will nevertheless contract on the exterior and through this contraction cause the straight edges of the plate to draw away from its axis a nd. thereby become of a larger diameter than when cast. By utilizing and controlling this contraction I am able to produce plates of all sizes from four sizes ofstock machines.

' To accomplish this control of the contraction l have made a cooling saddle with flexible sides or wings 71 arranged so as to c0ntract or expand with the plate during the coolingoperation, the wings 71 are composed of spring metal, and are normally of a curvature slightly smaller than the diameter of the concave face of the finished ribs P on the interior of the stereotype plate P. They are fixed to the sides of an overflow outlet 73 of a water distributing chamber 74 which is supported by pivots 75 on the frame G. The water chamber 74 is connected by a flexible tube 76, to a supply pipe 77 and a water controlling valve 78.

At each straight side of the wings are mounted rollers 80 for supportingthe stereotype plate as it is delivered by gravity from the finishing mechanism. Also mounted on each straight side of the wings are brackets 81 which extend beneath the edges of the stereotype plate and-have a lip 82 extending up so as to engage the outside edge of the stereotype plate. Beneath the wing brackets and supported by the frame are adjustable stops 83 which engage grooves 84, in the underside of the wing brackets when. the stereotype has contracted or expanded. the required amount as hereafter described.

The pivoted cooler. plate rollers, and brackets are normally'held on the same angle as the main shaft of the finishing mechanisin F by a spring 86 attached to an arm 87 fast to the pivot 75, and a pivoted latch S9.-is arranged to hold it at that angle during the delivery of the stereotype plate, but as the same plate positions itself by sliding down over the rollers from the finishing mechanism the beveled end of the plate engages the saidlatch and lifts it up. This releases it from engagement with the cooler whereupon the cooler and plate will turn to pivot 75, of the cooler. To one end of the plunger is fastened. a rod 94-, operating in a bearing. It is provided with a spring actuated latch 95 in the path of a pin 96, positioned upon the lever 92 so that when the cooler turns on its pivot the pin engages the latch and opens the valve allowing the water to flow up into the cooler water distributing chamber and overflow between the hot stereotype plate and flexible wings. As the outlet for the water is confined to, the space between the wings 71 and concave face of the stereotype plate. which spaceis less in cross section than the inlet. the water will be held under pressure against the stereotype plate and drive ahead any steam that may form, thereby causing very quick action in cooling the stereotype plate. A stop 99 limits the rocking of the saddle.

For the purpose of stopping the flow of water before the stereotype plate is entirely cold and allowing it to drain free from the plate so thatthe heat remaining will evaporate any moisture remaining, any desired construction can be'used as for instance. a valve which opens automatically in a given time, but I have shown a friction driven timing mechanism composed of a wheel 20 mounted on a'stud 21 on an arm 22. This arm is pivoted to the frame G, by a stud 23. This wheel is intermittently driven by a small pin 2 axially mounted on the end ofthe worm cross shaft 31. Normally facing this pin is a recess 26. formed across the face of the wheel. To the side of the wheel is fixed a pin 27 which is engaged by a pro jection 28 formed on; the lower end of the arm 92, and positioned so that as the cooler turns to horizontal position it'will cause the said projection to engage the pin and turn. the wheel ahead so that pin 24:, normally revolving in the recess 26. engages the face of the wheel 20 and causes said wheel to make one revolution. At the end of they revolution a second pin 30 engages and trips the valve-plunger latch 95, which action causes the valve to close and the flow of water to stop. 'A drip opening 32 is positioned near the over flow of the cooler which allows all water above the said drip to escape so that when the stereotype plate is being lifted. (which action allows the cooler to be turned by its spring 86- into alignment with the main shaft and in position to receive the following stereotype plate), there is no danger of splashing the stereotype which is now cooled and dried.

By this combination of water control I not only require less water, as by actual test a plate can be sufficiently cooled after a water contact of three seconds, and achain ing and evaporating lapse of three seconds less.

cooler by the bare hands. This regulation of the water dispenses with brushes or any other means of wiping the plate dry as has been the practice heretofore.

During the cooling operation, as stated, the stereotype plate contracts first on the interior and then, as the cooling advances through the plate on the exterior. This is due to the cooling water engaging the concavity of the stereotype only.

The means employed for controlling the contraction as previously stated comprises adjustable stops 83 which engage the brackets 81 attached to the flexible wings of the cooler, the stereotype plate being held against the wings by projections 82 on the bflackct overlapping the straight edges of the stereotype plate. So if it is desired to reduce the curvature the adjustable stops are axially moved to the diameter desired so when the hot plate rolls down over the cooler and trips the latch 89, the cooler turns on its pivot until the bracket 81 engages the top of the adjustable stop as shown in Fig. 4. The act of tipping the cooler having opened the .valve, the water rushes into contact with the concave side of the stereotype plate which causes the inside of the stereotype plate to contract, thereby reducing the diameter. This causes the wings carrying the grooved bracket to move axially inward until the groove Sl is just above enter and engage the groove, as shown in Fig. 5 thereby holding the stereotype plate and wings against any further flexing of the stereotype plate in either direction, and thereby leaving the stereotype of a less diameter than when cast. To cause the stereotype to be of a greater diameter after cooling than when cast, the adjustable stop 83 is moved axially out to the desired diameter. See F 6. If the full limit of expansion is required the stop is moved. so it will engage the projection 39 on the lower side of the bracket 81 which will prevent any interior contractions, but as the exterior cools the contraction on the, outer side will cause the stereotype plate to open out until the lip of the adjustable stop' engages the groove as. in the opposite direction. See Fig. 5. However, if a lesser expansion of the diameter is desired the step should be moved out Then the action will he, first an in terior and closing-in contraction which will cause the projection 39 on the bracket to en gage the stop 83, and upon the exterior contraction taking place the stereotype plate will expand until the lip of the adjustable stop enters the groove of the bracket and re sists further expansion of the diameter of the stereotype plate. If the plate is cooled on the exterior iustcai'l of on the interior the process will-be modified accordingly.

Beneath the cooler a sink 4 .0 is formed for catching the waste w ter which sinlr is provided with a pipe for carrying the water away.

The cooling apparatus is not claimed herein as it is incliuled in my above.montioned application Serial. No. 159,117.

l v hile Ihavo illustrated and described a preferred embodiment of the invention 1 am aware of the fact that many modifications can be made therein by any person skilled in the art without departing from the scope of the invention. Therefore I do not wish to be limited to all the details of construction herein shown and described except as defined in the appended claims, but what I claim is 1. A method of cooling curved cast plates to control the diameter hereof, which consists in applying a cooling fluid to one curved surface of a plate and preventing its contact with the other curved surface there of, and positively controlling the contraction and expansion of the plate by limiting the motion of the straight edges of the plate toward or from each other.

2. A method of cooling curved stereotype printing plates which consists in applying a cooling fluid to the interior concave surface thereof and preventing its application to the exterior surface, allowing the opposite straight edges to approach each other at will by contraction and then limiting the subsequent drawing apart of said edges.

A. n'iethod of cooling curved stereotype printing plates which. co sists in applying a. cooling sold to the interior concave surface thereof and preventing its application to the exterior surface. allowing the opposite straight edges to approach each other at will by cont action and then limiting the subsequent drawing apart of said edges bv expansion whereby the plate produced will be smaller in diameter than the plate as cast.

4-. A method of cooling and drying a curved stereotype printing plate which consists in apply cooling water thereto to partly cool the place, then discontinuing the application of cooli. water and allowing the plate to continue to cool whereby the leatremaining in the plate will evaporate the water on the surface thereof and dry it.

A method of cooling curved stereotype printing plates, which. consists in applying a cooli fluid exclusively to the interior of said pla es and i'listributing it along the en tire interior surface, positively limiting the extent of contraction of the plate inwardly toward the axis thereof, and then allowing the cooling of the plate to extend through the plate and permitting free expansion of the plate outwardly.

part of the cooling operation and then allowing them to draw apart by the subsequent expansion, whereby the cooled plate Will be oi larger diameter thanthe plate. as cast;

In testimony whereof I have hereunto affixed my signature.

GHARLED E. HOPKINS. 

